GM Service Manual Online
For 1990-2009 cars only

Vehicles with the engine coolant heater can use this option in cold weather conditions at or below 0°F (-18°C) for easier starting and better fuel economy during engine warm-up. Plug in the coolant heater at least four hours before starting your vehicle. An internal thermostat in the plug-end of the cord may exist which will prevent engine coolant heater operation at temperatures above 0°F (-18°C).

To Use the Engine Coolant Heater

  1. Turn off the engine.
  2. Open the hood and unwrap the electrical cord. The cord is located near the driver side strut tower.
  3. Remove the plastic cap to access the plug.

  4. Plug it into a normal, grounded 110-volt AC outlet.
  5. Caution: Plugging the cord into an ungrounded outlet could cause an electrical shock. Also, the wrong kind of extension cord could overheat and cause a fire. You could be seriously injured. Plug the cord into a properly grounded three-prong 110-volt AC outlet. If the cord will not reach, use a heavy-duty three-prong extension cord rated for at least 15 amps.

  6. Before starting the engine, be sure to unplug and store the cord as it was before to keep it away from moving engine parts. If you do not, it could be damaged.

Contact your dealer/retailer for information on how long to use the heater in your particular area.